import React, { Component } from 'react'
import Child from './Child'

export default class Parent extends Component {

  state = {
    hasError: '', // 用于标识子组件是否产生错误
  }

  // 当Parent的子组件出现报错时候，会触发getDerivedStateFromError调用，并携带错误信息
  static getDerivedStateFromError (error) {
    console.log('@@@', error);
    return {hasError: error}
  }


  render() {
    // console.log(this.state.count)
    return (
      <div>
        <h2>我是Parent组件</h2>
        {
          this.state.hasError ? <h2>当前网络波动， 稍后再试！</h2> : <Child />
        }
      </div>
    )
  }
}
